I have a Lionel SW switcher that is supposed to be 0-27, but the long roller arms are really an 0 design and slightly worn wheels now allow the front roller to drop off the center rail so for 0-27 I have to zip tie the forward roller arm in a raised position. That similar to the coupler issue I mentioned. Too much arc from a small turn. (That GG can't use a 027 turnouts turn; bumps housing, too long. But can make a track turn at 027)
Adriatic posted:0-27 is good for a few oops steps at under 200lbs. O can take 300 just about all day long. There is a substantial difference. ...
when i hit 230 last winter i decided to turn things around. i was stalled at 210 for a few months, but recently have been increasing my walking and finally saw 208 last week. good to know i can start stepping on track again, hopefully by the new year. 
run healthy!
cheers...gary
Better watch that Marx track. I think its about 30 lbs lighter lol.
What brought me to my conclusive estimate?
My youthful extreme of fitness I was about 127 and running, mostly sprinting ten+ miles a day and walking on my hands a few hundred yards too. Older and stronger, but heavier, I was about 160. Then in my lazy 40s, 180-190 when I injured myself badly thinking I was still omnipotent. Not able to work, I had a huge living room floor set up I built from a crawling position. As I returned to living on two legs, I had hit 200 for the first time ever. My steps weren't too accurate yet, and over half a year maybe, I warped six or eight 027 gradually(warped meaning usable but visually very bad), and totally mangled one or two. My pals on the other hand are six huge guys, all brothers, and the lightest is a fit 260 ( think red headed descendants of German lumberjacks of Northern Michigan) About three or four missteps and 027 was mangled. But the O I replaced it with even took on another brother at 295 a whole lot. The eldest and youngest, both at about 320 and not sure footed, put a very slight warp in the O over about two weeks each, for each brother (1 month) All the O is still used on my 4.5x9, any 0-27 laid across path areas back then, got tossed.
Lionel O is strong, I pretty sure I've read Menards is about the same maybe heavier. I don't recall who made the statement, but others didnt give a conflicting report so I did assume it was accurate, and for the price, didn't give a few thousandths of metal much thought after that.
Hope that helps.
Oh, I peaked at 222, 2 years ago, but am back to 180 from being able to walk around better. That alone helped "tons" 
hlfritz posted:If you were doing a layout, new, first, modification, otherwise which would you use, and why?
I am leaning towards O-27 due to the ability to have smaller curves for the "narrow gauge" portion of my layout (smaller locos/cars).
I love the shorter rail height of O27 rail...I kiddingly call it finer-scale hi-rail. Perfect for my long planned proto-based, linear and micro/mini inspired new around the room new short line layout. I've been collecting K-Line turnouts for a while now and narrow benchwork shelves begin this winter; road switchers and shorter cars are perfect for this rural line and everything I've run works on the curves. Divided into scenes, major corners will be scenery hidden; one background behind-the-scenes track will represent mainline and hidden (except at the interchange) will be standard O rail. Everything else and 99% of the layout is O27 based.
